Friday, April 30, 2010

Abstract [edit]: We describe an early-juvenile specimen and a late-juvenile specimen, both referable to the oviraptorosaur Similicaudipteryx, recovered from the Lower Cretaceous Yixian Formation of western Liaoning, China. The two specimens have strikingly different remiges and rectrices, suggesting that a radical morphological change occurred during feather development, as is the case for modern feathers.

However, both the remiges and the rectrices are proximally ribbon-like in the younger specimen but fully pennaceous in the older specimen, a pattern not known in any modern bird.

In combination with the wide distribution of proximally ribbon-like pennaceous feathers and elongate broad filamentous feathers among extinct theropods, this find suggests that early feathers were developmentally more diverse than modern ones and that some developmental features, and the resultant morphotypes, have been lost in feather evolution.

Note: The blog will be taking a short break until the middle of next week.

Leidy is known as the "Father of American Vertebrate Paleontology". He described the first relatively complete dinosaur skeleton, Hadrosaurus, and introduced many American and European scientists to the fossil riches of the American West. Leidy's consummate skill in comparative anatomy would allow him to identify and characterize even the most fragmentary fossil material.

Leidy was also the "Founder of American Parasitology," a Professor of Anatomy at the University of Pennsylvania, a pioneering protozoologists, an influential teacher of Natural History, an accomplished microscopist and scientific illustrator, and an expert on a variety of subjects encompasing the earth and natural sciences. He published scientific papers on more than a thousand extinct and living protozoa, fungi and invertebrates and vertebrates as well as an assortment of publications on human biology and medicine. He was also one of the earliest supporters of Charles Darwin.

Tuesday, April 27, 2010

Mice have a ribcage with 12 pairs of ribs (top). When the gene Hox6 is activated in ribless regions of the embryo, extra ribs are formed, extending from the ribcage to the tail (bottom). Image: M. Mallo.

Making ribs is not the default state for vertebrates, but is actually an active process of balancing the activities of a remarkable class of genes - the Hox genes.

It was thought that the rib less region of the mouse embryo was the result of a rib-inhibiting programme, driven by Hox10 genes. Indeed, previous studies, in which Hox10 genes were inactivated in the embryo, generated mice with extra ribs. However, by forcing another class of Hox genes (Hox6) to be activated in future rib-less regions of the mouse embryo, scientists have bred mice that also have extra ribs, both in the neck area, and from just after the rib cage, all the way down to the tail, resembling a snake-like skeleton.

These two groups of Hox genes balance each other out: one actively promotes rib formation to produce the thoracic region, while the other blocks this activity in the lumbar region. The whole process relies on first hitting so-called muscle genes in the embryo, which then provide signals to switch on the 'rib' genes to make both ribs and muscle, in a coordinated process. link

Abstract [edit]: Distributional data for Cretaceous dinosaur and plant groups were mapped onto palaeogeographical reconstructions in a series of time-slices. Within each time-slice, palaeocontinental surfaces were divided into a series of grids, each of which was scored as present, absent or inapplicable (unsampled) for each group. Distributions were compared statistically to determine whether the putative coevolving groups co-occurred within grid squares more or less frequently than expected by chance.

Pairwise comparisons were made between herbivorous dinosaur clades and major plant groups (e.g. cycads, angiosperms) on a global scale. Only three nonrepeated associations of marginal significance were recovered, demonstrating that, in general, current knowledge of the spatiotemporal distributions of these groups provides little support for coevolutionary hypotheses.

Back on this day in 1956 the second sequel to The Creature From the Black Lagoon debuted. It's long been considered the weakest film in the trilogy, and it's hard to argue this given that they drag The Creature out of the Amazon, burn him in a fire, and convert him into an air-breathing humanoid with no hope of ever returning to the lagoon. But, when viewed today, the film reveals some deeper tones than I'm sure were originally intended.

The plot and language of the film can now be taken to speak directly to the hot-button topics of genetic manipulation of animals and foods, and man's destructive meddling with nature leading to accelerated rates of extinction. The movie moves beyond being a simple “monster on the rampage” story and actually has some pointed comments to make about science and politics. It's well worth watching on one of those upcoming hot, humid summer nights.

Watch the film in 8 minutes thanks to the Castle Films Super 8mm edited home version:

Suess (Aug. 20, 1831 – April 26, 1914) was an Austrian geologist who helped lay the basis for paleogeography and tectonics. He was an authority on structural geology, especially of mountains, and postulated the existence of the giant land mass Gondwanaland.

While he was a professor (1857–1901) at the Univ. of Vienna, he also served for more than 20 years in the Austrian parliament. His Austrian-born son, Hans Suess, became a geochemist who pioneered radiocarbon dating techniques and was a founding faculty member of the University of California, San Diego.

Sunday, April 25, 2010

Cartoonist and rock ‘n roller, Tom Bagley, also one of the 7 Deadly Sinners, recently sent me this past from his past – a childhood visit to Dinosaur Land in Muskoka, Ontario. That’s Tom (left) and his brother helping Mary Anning excavate an ichythosaur. This place seems to have literally vanished off the face of the Earth, so if anyone has any info about it I’d appreciate hearing it.

Tom adds:

"They even had a caveman village down in a valley that I'm sure was pretty spectacular. The coolest part was that you went into a little theatre that ran "A World Is Born" (the "Rite of Spring" sequence from Fantasia) continuously."

An examination of the DNA of 1,983 people from around the globe suggests that extinct human species such as Homo neanderthalensis or Homo heidelbergensis interbred with our own ancestors during two separate periods, and their genes remain in our DNA today. The findings mean Neanderthals did not completely disappear, but “there is a little bit of Neanderthal left over in almost all humans.”

Scientists studying fossils and minerals from Arctic Svalbard, in Norway, have discovered evidence that the ‘greenhouse’ climate of the Cretaceous period was punctuated by a sudden drop in global temperatures.

The drop is estimated to have occurred some 137 million years ago during a time when dinosaurs roamed the Earth, and would have seen the islands fall from an average of 13°C (ocean temperature) to as low as four degrees.

Despite being located in the Arctic Circle, Svalbard was home to numerous species of dinosaur and was typically characterised by warm, shallow seas and swamps. But the researchers found evidence in fossils and carbonate materials preserved in marine rocks in the region of a transient shift to cooler glacial conditions around 137 million years ago.

“But over a period of a few hundred or a few thousand years, ocean temperatures fell from an average of 13°C to between eight and four degrees.

“Although a short episode of cool polar conditions is potentially at odds with a high CO2 world, our data demonstrates the variability of climate over long timescales.” link

Friday, April 23, 2010

Flavin (May 14, 1906 – April 23, 1976) starred in his first film (The Airmail Mystery) in 1932. After that he played mostly supporting characters in nearly four hundred films between 1932 and 1971, and in almost a hundred television episodes. He takes a bow here for playing Second Mate Briggs in King Kong (1933).

Wednesday, April 21, 2010

I’d forgotten that Mark Twain (November 30, 1835 – April 21, 1910) had written about dinosaurs.

Illustration from first edition of EVE'S DIARY

"When the mighty brontosaurus came striding into camp, she regarded it as an acquisition, I considered it a calamity; that is a good sample of the lack of harmony that prevails in our views of things. She wanted to domesticate it, I wanted to make it a present of the homestead and move out. She believed it could be tamed by kind treatment and would be a good pet; I said a pet twenty-one feet high and eighty-four feet long would be no proper thing to have about the place, because, even with the best intentions and without meaning any harm, it could sit down on the house and mash it, for any one could see by the look of its eye that it was absent-minded." - Eve's Diary

"The less said about the pterodactyl the better. It was a spectacle, that beast! a mixture of buzzard and alligator, a sarcasm, an affront to all animated nature, a butt for the ribald jests of an unfeeling world. After some ages Nature perceived that to put feathers on a reptile does not ennoble it, does not make it a bird, but only a sham, a joke, a grotesque curiosity, a monster; also that there was no useful thing for the pterodactyl to do, and nothing likely to turn up in the future that could furnish it employment. And so she abolished it." - "Flies and Russians," Fables of Man

Catalan researchers have discovered in the rubbish dump a new species of Pliopithecus primate, considered an extinct family of primitive Catarrhini primates (or "Old World monkeys"). The fragments of jaw and molars found in this large site demonstrate that Pliopithecus canmatensis belongs to this group, which includes the first Catarrhini that dispersed from Africa to Eurasia.

Named Pliopithecus canmatensis, in honour of the place they were discovered in Catalonia, the new fossil species sheds light on the evolution of the superfamily of the Pliopithecoidea, primates that include various genera of basal Catarrhini, a group that diverged before the separation of the two current superfamilies of the group: the cercopithecoids (Old World monkeys) and the hominoids (anthromorphs and humans); and which prospered in Eurasia during the Early and Late Miocene (between 23.5 and 5.3 million years ago).

“These eight remarkable Albertans have all made very positive contributions to our province, and they have done so while forging a unique path and encouraging others to follow their lead," said outgoing Alberta Lieutenant-Governor Norman Kwong, who's also chancellor of the Order. link

Hennig (April 20, 1913 – Nov. 5, 1976) is best known for developing phylogenetic systematics, a coherent theory of the investigation and presentation of the relations that exist among species. Contrary to the position generally held during his time, Hennig viewed historical inference as a strictly logical and scientific endeavor. He first summarized his ideas in 1950 in German which became more widely known with the publication of the English revision, Phylogenetic Systematics (Hennig, 1966).

1. Relationships among species are to be interpreted strictly genealogically, as sister-lineages, as clade relations. Empirically, a phylogenetic hypothesis may be determined.

2. Synapomorphies provide the only evidence for identifying relative recency of common ancestry. Synapomorphies are understood to be the shared-derived (evolved, modified) features of organisms.

3. Maximum conformity to evidence is sought (his auxiliary principle). Choice among competing cladistic propositions (cladograms) is decided on the basis of the greatest amount of evidence, the largest number of synapomorphies explainable as homologues.

4. Whenever possible, taxonomy must be logically consistent with the inferred pattern of historical relationships. The rule of monophyly is to be followed, thereby each clade can have its unique place in the hierarchy of taxonomic names.

Logan (April 20, 1798 – June 22, 1875) was a Canadian geologist dubbed the "Father of Canadian Geology." He began is career making geologic maps of coalfields in Wales, noting the relationship between the underlying clay layers and fossil tree roots with local coal beds. This substantiated the theory that coal beds are formed in place.

When he began as director (1842-69) of the new Geological Survey of Canada, its geology was virtually unknown. He produced the monumental Report on the Geology of Canada (1863) which recorded 20 years of research, fieldwork, plotting maps, preparing reports, and examining fossil and mineral specimens.

Armstrong (Nov. 20, 1890 – April 20, 1973) took Fay Wray to Skull Island in 1933. He returned later the same year to find The Son of Kong, only to lose him as the island sank, as these things are prone to doing.

Louis Antoine Marie Joseph Dollo (Dec. 7, 1857 – April 19, 1931) was a French vertebrate paleontologist who stated Dollo's Law of Irreversibilitywhereby in evolution an organism never returns exactly to its former state such that complex structures, once lost, are not regained in their original form. (While generally true, some exceptions are known.)

He began as an assistant (1882), became keeper of mammals (1891) at the Royal Museum of Natural History in Brussels where he stayed most of his life. He was a specialist in fossil fishes, reptiles, birds, and their palaeoecology.

He supervised the excavation of the famous, multiple Iguanodons found in 1878 by miners deep underground, at Bernissart, Belgium.image

Sunday, April 18, 2010

Bill Benson at The Value discusses how Walt Disney put Charles Darwin front and center in The Rite of Spring section of the film Fantasia.

Fish with legs

"But let us return to the metamorphosis sequence. Obviously this sequence does not depict Darwinian evolution in any direct way. If one did not know what it was meant to depict, the sequence would be mysterious. The important point is that, given the various implicit conventions Disney has already established in the three previous segments of Fantasia, we have no choice but to understand this metamorphosis as something that has been driven from within the animal itself. There is no external force acting on the animal, no Divine Designer."

Michael Barrier (where I found Benson’s article) follows up on Benson’s suggestion that “the fundamentalists, according to John Hubley, threatened to make trouble for Fantasia if Walt connected evolution with human beings.” Interesting reading, especially for those of us old enough have been exposed to The Rite of Spring in grade school science class.

“Meanwhile, the light-skinned Noble Johnson (April 18, 1881 – Jan. 9, 1978) was heavily made up for his role as the village chief [in 1933's, KING KONG]—he was a leading black actor of the era (known as “America’s premiere Afro-American screen star” in the black press) and therefore worth the extra consideration. Johnson, an ex-cowboy, horse trainer, and boxer, had quite a resume before portraying the Chief of Skull Island.

He was a student of all aspects of movie making from directing to distribution, and instrumental in the 1916 formation of the Lincoln Motion Picture Company, created to produce what were called “race movies.” Johnson left the company after it had released three films, rumored to have been “encouraged” by Universal to do so or lose any opportunity for parts at the bigger studio.

Johnson - a childhood friend of Lon Chaney - portrayed a variety of ethnicities in his long career; one of the few black actors of Hollywood’s early era to be allowed any diversity in roles.” From Kong Is King.net

Erasmus (Dec. 12, 1731 – April 18, 1802.) was a prominent English physician, poet, philosopher, botanist, naturalist and the grandfather of naturalist Charles Darwin and the biologist Francis Galton. Erasmus Darwin was one of the leading intellectuals of 18th century England.

As a naturalist, he formulated one of the first formal theories on evolution in Zoonomia, or, The Laws of Organic Life (1794-1796). Although he did not come up with natural selection, he did discuss ideas that his grandson elaborated on sixty years later, such as how life evolved from a single common ancestor, forming "one living filament".

Although some of his ideas on how evolution might occur are quite close to those of Lamarck, Erasmus Darwin also talked about how competition and sexual selection could cause changes in species.link

Saturday, April 17, 2010

The news began bubbling out over the weekend: "Missing link between man and apes found," declared an April 3 story in the London Telegraph. When I saw that headline, I thought to myself, "Please, please, not again."

Bayes (1702 – April 17, 1761) was a English theologian and mathematician who was the first to use probability inductively and who established a mathematical basis for probability inference (a means of calculating, from the frequency with which an event has occurred in prior trials, the probability that it will occur in future trials).

This became the basis of a statistical technique, now called Bayesian estimation, for calculating the probability of the validity of a proposition on the basis of a prior estimate of its probability and new relevant evidence. link

This has been used to develop the program Mr. Bayes for the Bayesian estimation of phylogeny. Bayesian inference of phylogeny is based upon a quantity called the posterior probability distribution of trees, which is the probability of a tree conditioned on the observations. The conditioning is accomplished using Bayes's theorem. The posterior probability distribution of trees is impossible to calculate analytically; instead, MrBayes uses a simulation technique called Markov chain Monte Carlo (or MCMC) to approximate the posterior probabilities of trees. link

Directed by Carl Gottlieb and starring Ringo Starr, this film is probably best known for introducing Starr to his future wife, Barbara Bach. Famed Animator Jim Danforth oversaw the creation of the dinosaurs.

Friday, April 16, 2010

Abstract [edit]: All forms of life require and concentrate phosphorus, and as a result of biological processing, modern marine phosphates have δ18OP values typically between 19–26‰ (VSMOW), highly evolved from presumed source values of ~6–8‰ that are characteristic of apatite in igneous rocks and meteorites.

Here we report oxygen isotope compositions of phosphates in sediments from the 3.2–3.5-billion-year-old (Palaeoarchaean) Barberton Greenstone Belt in South Africa. We find that δ18OP values range from 9.3‰ to 19.9‰ and include the highest values reported for Archaean rocks.

The temperatures calculated from our highest δ18OP values and assuming equilibrium with sea water with δ18O = 0‰ (ref. 12) range from 26 °C to 35 °C. The higher δ18OP values are similar to those of modern marine phosphate and suggest a well-developed phosphorus cycle and evolved biologic activity on the Archaean Earth.

Buffon (Sept. 7, 1707 – April 16, 1788) was a French naturalist, who formulated a crude theory of evolution and was the first to suggest that the earth might be older than suggested by the Bible. In 1739 he was appointed keeper of the Jardin du Roi, a post he occupied until his death. There he worked on a comprehensive work on natural history, for which he is remembered, Histoire naturelle, générale et particulière. He began this work in 1749, and it dominated the rest of his life. It would eventually run to 44 volumes, including quadrupeds, birds, reptiles and minerals. He proposed (1778) that the Earth was hot at its creation and, from the rate of cooling, calculated its age to be 75,000 years, with life emerging some 40,000 years ago.

Rosalind Franklin (July 25, 1920 - Apr. 16, 1958) was an English scientist who contributed to the discovery of the molecular structure of deoxyribonucleic acid (DNA), a constituent of chromosomes that serves to encode genetic information. Beginning in 1951, she made careful X-ray diffraction photographs of DNA, leading her to suspect the helical form of the molecule, at least under the conditions she had used.

When Watson saw her photographs, he had confirmation of the double-helix form that he and Crick then published. She never received the recognition she deserved for her independent work, but had died of cancer four years before the Nobel Prize was awarded to Crick and Watson.

Sloane (Apr. 16, 1660 - Jan. 11, 1753) was a British physician and naturalist whose collection of books, manuscripts, and curiosities formed the basis for the British Museum in London. By the time he died, Sloane had amassed one of the world's largest and most varied collections of natural history specimens. His passion for the collection and his concern for its future upkeep after his death led him to write a will which clearly stated that it must "remain together and not be separated."

He offered it to the British nation, requesting in return a sum of £20,000 for his heirs. Parliament accepted, and King George II gave his royal assent 7 Jun 1753. Thus the British Museum was created and eventually its sister institution, the British Museum of Natural History. image

Thursday, April 15, 2010

Archimylacris eggintoni, an early ancestor of the cockroach has been unveiled in unprecedented detail in a new three-dimensional 'virtual fossil' model. This insect scuttled around on Earth during the Carboniferous period 359 - 299 million years ago, which was a time when life had recently emerged from the oceans to live on land.

The 3D model also reveals how Archimylacris eggintoni's legs could help it to run fast. The team noted that the legs were at a low angle to the body and fairly long, which they believe helped it to move quickly even when the terrain was difficult or uneven.

It also had sticky structures on its legs called euplantulae to help them stick to smooth surfaces such as leaves as they climbed across them.

In addition, the scientists also discovered that Archimylacris eggintoni had claws at the base of its legs, which helped it to climb rough surfaces like trees, so that it could perch above the forest floor for safety or find alternate sources of food higher up.

Mr Garwood adds: "We now think this ancient ancestor of the cockroach spent most of the day on the forest floor, living in and eating lots of rotting plant and insect matter, which was probably the bug equivalent of heaven. We think it could have used its speed to evade predators and its climbing abilities to scale trees and lay eggs on leaves, much in the same way that modern forest cockroaches do today."

It’s April 15th and if you’re in the US you’ve just filed your taxes. So why not sit back and watch a truly bad movie on the HiDef, Big Screen soul sucker that controls your life? Or you can just watch the MST3K version on YouTube like regular folk do.

Diamond Select Toys will soon be selling their latest Star Trek toy - the Geological Tricorder. Following the release of the Medical and Science Tricoders, the Geological Tricoder will feature two opening compartments and removable vials of mineral samples. Take that iPhone!Thanks to the Atomic Surgeons for this!

Wednesday, April 14, 2010

As of today the 2nd Annual Visual Culture and Evolution Online Symposium wrapped up. The symposium brought together more than 30 international experts - including artists, scientists, historians, ethicists, curators, sociologists, and writers – to discuss the intersections between the visual arts and evolution. The symposium was a platform to discuss the impact of evolutionary thought on visual culture.

The following is posted for the son of Demberel Dashzeveg, the Mongolian paleontologist who passed away last month

Dear all,

My father Demberel DASHZEVEG passed way on March 28th 2010. He was born in 1936 in Ero, a town in the Selenge Province of Mongolia. Dr. Dashzeveg taught in the Mongolian University from 1961 to 1963, and then was a scientist in the Mongolian Academy of Sciences (MAS) from 1965 to 2009. Academician Dashzeveg was a member of the Mongolian-Russian Paleontological expedition, the Mongolian-Polish Paleontological expedition, and explored the Gobi Desert for more than 40 years. Dr. Dashzeveg worked as a co-leader of the Mongolian-American Paleontological expedition (MAE) from 1990 to 2007.

Dr. Dashzeveg was a first-rate scientist, who founded the science of paleontology in Mongolia and represented Mongolian paleontology internationally in his scientific writings, his presentations, and as a curator of the Mongolian Paleontological exhibition in Japan 1984-87. The explorations, discoveries, and publications of my father will last as useful testimony to all the paleontologists and geologists of the world, and to the next generation of scientists. The Mongolian people and the Mongolian Government rewarded Dr. Dashzeveg for these achievements by bestowing on him the award of "Honorary Member of Sciences", valuing his high contribution inpaleontology and stratigraphy.

American paleontologist Philip D. Gingerich wrote in a letter to me that "Dashzeveg represented Mongolia and paleontology as a pioneer on an international stage, and he made many great contributions to our subject! It was a privilege and an honor to know him and especially to collaborate in research!" Michael Novacek, Vice President of the AMNH wrote in his book Dinosaurs of the Flaming Cliffs, "Dr. Demberel Dashzeveg, a world-famous paleontologist and our Mongolian colleague, knew the Gobi Desert perhaps better than any person alive. Dashzeveg, a man in his late fifties, was tall and wiry, with the lean and hungry look of a Siberian wolf, the dark wrinkled skin of his face burnished by years of desert winds." All the members of the MAE called my father "the King of the Gobi".

His patriotism, hard work, honesty and friendliness will always remain in our souls and memories.

Tuesday, April 13, 2010

This year will mark the 70th anniversary of the Society of Vertebrate Paleontology. One of the few photos from the early days that I've been able to find comes from David Evans' lab at the Royal Ontario Museum. The photo is glued in a picture frame and covered with glass, so thanks to Caleb Brown for taking the best photograph of it possible. It'll bet it originally came from Loris Russell.

What began as a friendly rivalry in the late 1860s, broke out into all out war in 1872 and then raged on until Cope's death in 1897.

Both Cope and Marsh were recipients of family fortunes and they used their wealth to discover new fossils and to reconstruct ancient life. This scramble literally propelled American science into the forefront of paleontology."

How did dinosaurs endure up to six months of cold and total darkness? Fossils from Australia are slowly revealing the strange story of polar dinosaurs. Read a reprint of the article from Smithsonian on-line at Cosmos Magazine.

The fossils of Australopithecus sediba are between 1.95 and 1.78 million years old, and show that the new species was an upright walker that shared many physical traits with the earliest known Homo species.

These new fossils are approximately one million years younger than the famous Australopithecus, Lucy, and their features imply that the transition from earlier hominids to the Homo genus occurred in very slow stages, with various Homo-like species emerging first.

The fossil remains of the two hominids were found about a half-meter apart, embedded in cave deposits at the Malapa excavation site located about 170 miles northeast of Johannesburg and about nine miles northeast of the Sterkfontein World Heritage Site, also called the Cradle of Humankind. The first adult australopithecine was found in Sterkfontein in 1936.

It is not possible to establish the precise phylogenetic position of Australopithecus sediba in relation to various species assigned to early Homo. The new species shares more derived features with early Homo than any other known australopith species, and thus represents a candidate ancestor for the genus, or a sister group to a close ancestor that persisted for some time after the first appearance of Homo."

The researchers describe the hominid's physical traits, highlighting the unique pelvic features and small teeth that it shared with early Homo species. Based on its physique, they suggest that the new species descended from Australopithecus africanus, and that the hominid's appearance signified the dawn of more energy-efficient walking and running. link

Wednesday, April 07, 2010

Oakley (April 7, 1911 - November 2, 1981) was an English physical anthropologist, geologist, and paleontologist best known for his work in the relative dating of fossils by fluorine content. While working for the British Natural History Museum, Oakley become famous in 1953 for exposing the 'Piltdown Man' forgery.

"A skull had been "unearthed" in 1912, in Piltdown, England, and had for decades been said to represent the "missing link" in human evolution. Oakley developed a method, based on a French minerologist's theory that bones would gradually absorb fluorine from surrounding soil, to measure the fluorine levels in bones. With this and other tests he proved the bones to be a modern human braincase and an orangutan jawbone chemically stained to appear ancient. image

Tuesday, April 06, 2010

Watson was born on this day in 1928. An American geneticist and biophysicist, he shared the 1962 Nobel Prize for Physiology or Medicine (with Francis Crick and Maurice Wilkins) for the discovery of "the molecular structure of nucleic acids and its significance for information transfer in living material." Deoxyribonucleic acid (DNA) is the substance contained in cells that controls heredity.

Crick and Watson began their collaboration in 1951, and published their paper on the double helix structure on 2 Apr 1953 in Nature. This accomplishment became a cornerstone of genetics and was widely regarded as one of the most important discoveries of 20th-century biology.image.

The museum began from the efforts of Albert Smith Bickmore, one-time student of Harvard zoologist Louis Agassiz, who was successful in his proposal to create a natural history museum in New York City, with the support of William E. Dodge, Jr., Theodore Roosevelt, Sr., Joseph Choate, and J. Pierpont Morgan. It opened to the public 27 Apr 1871.

With a series of exhibits, the Museum’s collection went on view for the first time in the Central Park Arsenal, the Museum’s original home, on the eastern side of Central Park.

Also, on this day in 1930, Hostess Twinkies were invented by bakery executive James Dewar.

Monday, April 05, 2010

Sturtevant (Nov. 21, 1891 – April 5, 1970) was an American geneticist who in 1913 developed a technique for mapping the location of specific genes of the chromosomes in the fruit fly Drosophila. Sturtevant's method for "chromosome mapping", relies on the analysis of groups of linked genes.

In a classic paper in genetics (1913), he described the location of six sex-linked genes as deduced by the way in which they associate with each other.

Sturtevant later discovered the so-called 'position effect', in which the expression of a gene depends on its position in relation to other genes. He also demonstrated that crossing over between chromosomes is prevented in regions where a part of the chromosome material is inserted the wrong way round.

The father of radiation genetics, Muller (Dec. 21, 1890 – April 5, 1967) began his career with T.H. Morgan studying mutations in fruit flies. He was the first to increase the mutation rate using heat, later using 50 kilovolt X-rays to induce an even greater incidence of mutations. Muller was awarded the Nobel Prize for Physiology or Medicine in 1946.

Muller long warned about needless exposures to radiation and their associated risks of cancer and heritable genetic effects. By the late 1940s, the nuclear weapons testing program had begun and Muller was a vocal critic of the Atomic Energy Commission's views on the hazards of worldwide fallout.